testScheduleLaggyTaskAtFixedRate() — netty Function Reference

Source Code

transport/src/test/java/io/netty/channel/SingleThreadEventLoopTest.java lines 237–279

    private static void testScheduleLaggyTaskAtFixedRate(EventLoop loopA) throws InterruptedException {
        final Queue<Long> timestamps = new LinkedBlockingQueue<Long>();
        final int expectedTimeStamps = 5;
        final CountDownLatch allTimeStampsLatch = new CountDownLatch(expectedTimeStamps);
        ScheduledFuture<?> f = loopA.scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                boolean empty = timestamps.isEmpty();
                timestamps.add(System.nanoTime());
                if (empty) {
                    try {
                        Thread.sleep(401);
                    } catch (InterruptedException e) {
                        // Ignore
                    }
                }
                allTimeStampsLatch.countDown();
            }
        }, 100, 100, TimeUnit.MILLISECONDS);
        allTimeStampsLatch.await();
        assertTrue(f.cancel(true));
        Thread.sleep(300);
        assertEquals(expectedTimeStamps, timestamps.size());

        // Check if the task was run with lag.
        int i = 0;
        Long previousTimestamp = null;
        for (Long t: timestamps) {
            if (previousTimestamp == null) {
                previousTimestamp = t;
                continue;
            }

            long diff = t.longValue() - previousTimestamp.longValue();
            if (i == 0) {
                assertThat(diff).isGreaterThanOrEqualTo(TimeUnit.MILLISECONDS.toNanos(400));
            } else {
                assertThat(diff).isLessThanOrEqualTo(TimeUnit.MILLISECONDS.toNanos(10));
            }
            previousTimestamp = t;
            i ++;
        }
    }